1
|
Aydin S, Salehi SM, Töpfer K, Meuwly M. SCN as a local probe of protein structural dynamics. J Chem Phys 2024; 161:055101. [PMID: 39092954 DOI: 10.1063/5.0216657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 07/03/2024] [Indexed: 08/04/2024] Open
Abstract
The dynamics of lysozyme is probed by attaching -SCN to all alanine residues. The one-dimensional infrared spectra exhibit frequency shifts in the position of the maximum absorption of 4 cm-1, which is consistent with experiments in different solvents and indicates moderately strong interactions of the vibrational probe with its environment. Isotopic substitution 12C → 13C leads to a redshift by -47 cm-1, which agrees quantitatively with experiments for CN-substituted copper complexes in solution. The low-frequency, far-infrared part of the protein spectra contains label-specific information in the difference spectra when compared with the wild type protein. Depending on the position of the labels, local structural changes are observed. For example, introducing the -SCN label at Ala129 leads to breaking of the α-helical structure with concomitant change in the far-infrared spectrum. Finally, changes in the local hydration of SCN-labeled alanine residues as a function of time can be related to the reorientation of the label. It is concluded that -SCN is potentially useful for probing protein dynamics, both in the high-frequency part (CN-stretch) and in the far-infrared part of the spectrum.
Collapse
Affiliation(s)
- Sena Aydin
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Seyedeh Maryam Salehi
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Kai Töpfer
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| |
Collapse
|
2
|
Feng RR, Wang M, Zhang W, Gai F. Unnatural Amino Acids for Biological Spectroscopy and Microscopy. Chem Rev 2024; 124:6501-6542. [PMID: 38722769 DOI: 10.1021/acs.chemrev.3c00944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Due to advances in methods for site-specific incorporation of unnatural amino acids (UAAs) into proteins, a large number of UAAs with tailored chemical and/or physical properties have been developed and used in a wide array of biological applications. In particular, UAAs with specific spectroscopic characteristics can be used as external reporters to produce additional signals, hence increasing the information content obtainable in protein spectroscopic and/or imaging measurements. In this Review, we summarize the progress in the past two decades in the development of such UAAs and their applications in biological spectroscopy and microscopy, with a focus on UAAs that can be used as site-specific vibrational, fluorescence, electron paramagnetic resonance (EPR), or nuclear magnetic resonance (NMR) probes. Wherever applicable, we also discuss future directions.
Collapse
Affiliation(s)
- Ran-Ran Feng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Manxi Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Wenkai Zhang
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Feng Gai
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
3
|
Salehi SM, Meuwly M. Site-Selective Dynamics of Ligand-Free and Ligand-Bound Azidolysozyme. J Chem Phys 2022; 156:105105. [DOI: 10.1063/5.0077361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Markus Meuwly
- Department of Chemistry, University of Basel Department of Chemistry, Switzerland
| |
Collapse
|
4
|
Cross-Correlated Motions in Azidolysozyme. Molecules 2022; 27:molecules27030839. [PMID: 35164105 PMCID: PMC8838508 DOI: 10.3390/molecules27030839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/13/2022] [Accepted: 01/19/2022] [Indexed: 02/01/2023] Open
Abstract
The changes in the local and global dynamics of azide-labelled lysozyme compared with that of the wild type protein are quantitatively assessed for all alanine residues along the polypeptide chain. Although attaching -N3 to alanine residues has been considered to be a minimally invasive change in the protein it is found that depending on the location of the alanine residue, the local and global changes in the dynamics differ. For Ala92, the change in the cross-correlated motions are minimal, whereas attaching -N3 to Ala90 leads to pronounced differences in the local and global correlations as quantified by the cross-correlation coefficients of the Cα atoms. We also demonstrate that the spectral region of the asymmetric azide stretch distinguishes between alanine attachment sites, whereas changes in the low frequency, far-infrared region are less characteristic.
Collapse
|
5
|
Mukherjee D, Ahmed IA, Gai F. Site-Specific Interrogation of Protein Structure and Stability. Methods Mol Biol 2022; 2376:65-87. [PMID: 34845603 DOI: 10.1007/978-1-0716-1716-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
To execute their function or activity, proteins need to possess variability in local electrostatic environment, solvent accessibility, structure, and stability. However, assessing any protein property in a site-specific manner is not easy since native spectroscopic signals often lack the needed specificity. One strategy that overcomes this limitation is to use unnatural amino acids that exhibit distinct spectroscopic features. In this chapter, we describe several such unnatural amino acids (UAAs) and their respective applications in site-specific interrogation of protein structure and stability using standard biophysical methods, including circular dichroism (CD), infrared (IR), and fluorescence spectroscopies.
Collapse
Affiliation(s)
| | - Ismail A Ahmed
- Department of Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Feng Gai
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
6
|
Mondal P, Cazade PA, Das AK, Bereau T, Meuwly M. Multipolar Force Fields for Amide-I Spectroscopy from Conformational Dynamics of the Alanine Trimer. J Phys Chem B 2021; 125:10928-10938. [PMID: 34559531 DOI: 10.1021/acs.jpcb.1c05423] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dynamics and spectroscopy of N-methyl-acetamide (NMA) and trialanine in solution are characterized from molecular dynamics simulations using different energy functions, including a conventional point charge (PC)-based force field, one based on a multipolar (MTP) representation of the electrostatics, and a semiempirical DFT method. For the 1D infrared spectra, the frequency splitting between the two amide-I groups is 10 cm-1 from the PC, 13 cm-1 from the MTP, and 47 cm-1 from self-consistent charge density functional tight-binding (SCC-DFTB) simulations, compared with 25 cm-1 from experiment. The frequency trajectory required for the frequency fluctuation correlation function (FFCF) is determined from individual normal mode (INM) and full normal mode (FNM) analyses of the amide-I vibrations. The spectroscopy, time-zero magnitude of the FFCF C(t = 0), and the static component Δ02 from simulations using MTP and analysis based on FNM are all consistent with experiments for (Ala)3. Contrary to this, for the analysis excluding mode-mode coupling (INM), the FFCF decays to zero too rapidly and for simulations with a PC-based force field, the Δ02 is too small by a factor of two compared with experiments. Simulations with SCC-DFTB agree better with experiment for these observables than those from PC-based simulations. The conformational ensemble sampled from simulations using PCs is consistent with the literature (including PII, β, αR, and αL), whereas that covered by the MTP-based simulations is dominated by PII with some contributions from β and αR. This agrees with and confirms recently reported Bayesian-refined populations based on 1D infrared experiments. FNM analysis together with a MTP representation provides a meaningful model to correctly describe the dynamics of hydrated trialanine.
Collapse
Affiliation(s)
- Padmabati Mondal
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, Basel 4056, Switzerland
| | - Pierre-André Cazade
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, Basel 4056, Switzerland
| | - Akshaya K Das
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, Basel 4056, Switzerland
| | - Tristan Bereau
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, Basel 4056, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, Basel 4056, Switzerland.,Department of Chemistry, Brown University, Providence/RI 02912, United States
| |
Collapse
|
7
|
Thielges MC. Transparent window 2D IR spectroscopy of proteins. J Chem Phys 2021; 155:040903. [PMID: 34340394 PMCID: PMC8302233 DOI: 10.1063/5.0052628] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/21/2021] [Indexed: 02/01/2023] Open
Abstract
Proteins are complex, heterogeneous macromolecules that exist as ensembles of interconverting states on a complex energy landscape. A complete, molecular-level understanding of their function requires experimental tools to characterize them with high spatial and temporal precision. Infrared (IR) spectroscopy has an inherently fast time scale that can capture all states and their dynamics with, in principle, bond-specific spatial resolution. Two-dimensional (2D) IR methods that provide richer information are becoming more routine but remain challenging to apply to proteins. Spectral congestion typically prevents selective investigation of native vibrations; however, the problem can be overcome by site-specific introduction of amino acid side chains that have vibrational groups with frequencies in the "transparent window" of protein spectra. This Perspective provides an overview of the history and recent progress in the development of transparent window 2D IR of proteins.
Collapse
Affiliation(s)
- Megan C. Thielges
- Department of Chemistry, Indiana University, Bloomington,
Indiana 47405, USA
| |
Collapse
|
8
|
Tumbic GW, Hossan MY, Thielges MC. Protein Dynamics by Two-Dimensional Infrared Spectroscopy. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2021; 14:299-321. [PMID: 34314221 PMCID: PMC8713465 DOI: 10.1146/annurev-anchem-091520-091009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Proteins function as ensembles of interconverting structures. The motions span from picosecond bond rotations to millisecond and longer subunit displacements. Characterization of functional dynamics on all spatial and temporal scales remains challenging experimentally. Two-dimensional infrared spectroscopy (2D IR) is maturing as a powerful approach for investigating proteins and their dynamics. We outline the advantages of IR spectroscopy, describe 2D IR and the information it provides, and introduce vibrational groups for protein analysis. We highlight example studies that illustrate the power and versatility of 2D IR for characterizing protein dynamics and conclude with a brief discussion of the outlook for biomolecular 2D IR.
Collapse
Affiliation(s)
- Goran W Tumbic
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, USA;
| | - Md Yeathad Hossan
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, USA;
| | - Megan C Thielges
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, USA;
| |
Collapse
|
9
|
Abstract
The spectroscopic response of and structural dynamics around all azido-modified alanine residues (AlaN3) in lysozyme are characterized. It is found that AlaN3 is a positionally sensitive probe for the local dynamics, covering a frequency range of ∼15 cm-1 for the center frequency of the line shape. This is consistent with findings from selective replacements of amino acids in PDZ2, which reported a frequency span of ∼10 cm-1 for replacements of Val, Ala, or Glu by azidohomoalanine. For the frequency fluctuation correlation functions, the long-time decay constants τ2 range from ∼1 to ∼10 ps, which compares with experimentally measured correlation times of 3 ps. Attaching azide to alanine residues can yield dynamics that decays to zero on the few ps time scale (i.e., static component Δ0 ∼ 0 ps-1) or to a remaining, static contribution of ∼0.5 ps-1 (corresponding to 2.5 cm-1), depending on the local environment on the 10 ps time scale. The magnitude of the static component correlates qualitatively with the degree of hydration of the spectroscopic probe. Although attaching azide to alanine residues is found to be structurally minimally invasive with respect to the overall protein structure, analysis of the local hydrophobicity indicates that the hydration around the modification site differs for modified and unmodified alanine residues, respectively.
Collapse
Affiliation(s)
- Seyedeh Maryam Salehi
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| |
Collapse
|
10
|
Brünker P, Domenianni LI, Fleck N, Lindner J, Schiemann O, Vöhringer P. Intramolecular O-H⋯S hydrogen bonding in threefold symmetry: Line broadening dynamics from ultrafast 2DIR-spectroscopy and ab initio calculations. J Chem Phys 2021; 154:134305. [PMID: 33832237 DOI: 10.1063/5.0047885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dynamics of intramolecular hydrogen-bonding involving sulfur atoms as acceptors is studied using two-dimensional infrared (2DIR) spectroscopy. The molecular system is a tertiary alcohol whose donating hydroxy group is embedded in a hydrogen-bond potential with torsional C3-symmetry about the carbon-oxygen bond. The linear and 2DIR-spectra recorded in the OH-stretching region of the alcohol can be simulated very well using Kubo's line shape theory based on the cumulant expansion for evaluating the linear and nonlinear optical response functions. The correlation function for OH-stretching frequency fluctuations reveals an ultrafast component decaying with a time constant of 700 fs, which is in line with the apparent decay of the center line slopes averaged over absorption and bleach/emission signals. In addition, a quasi-static inhomogeneity is detected, which prevents the 2DIR line shape to fully homogenize within the observation window of 4 ps. The experimental data were then analyzed in more detail using a full ab initio approach that merges time-dependent structural information from classical molecular dynamics (MD) simulations with an OH-stretching frequency map derived from density functional theory (DFT). The latter method was also used to obtain a complementary transition dipole map to account for non-Condon effects. The 2DIR-spectra obtained from the MD/DFT method are in good agreement with the experimental data at early waiting delays, thereby corroborating an assignment of the fast decay of the correlation function to the dynamics of hydrogen-bond breakage and formation.
Collapse
Affiliation(s)
- Paul Brünker
- Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität, Wegelerstraße 12, 53115 Bonn, Germany
| | - Luis I Domenianni
- Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität, Wegelerstraße 12, 53115 Bonn, Germany
| | - Nico Fleck
- Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität, Wegelerstraße 12, 53115 Bonn, Germany
| | - Jörg Lindner
- Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität, Wegelerstraße 12, 53115 Bonn, Germany
| | - Olav Schiemann
- Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität, Wegelerstraße 12, 53115 Bonn, Germany
| | - Peter Vöhringer
- Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität, Wegelerstraße 12, 53115 Bonn, Germany
| |
Collapse
|
11
|
Zhang H, Lai H, Li G, Hu Y. 4-Aminothiophenol capped halloysite nanotubes/silver nanoparticles as surface-enhanced Raman scattering probe for in-situ derivatization and selective determination of nitrite ions in meat product. Talanta 2020; 220:121366. [DOI: 10.1016/j.talanta.2020.121366] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 06/14/2020] [Accepted: 06/15/2020] [Indexed: 01/03/2023]
|
12
|
Abstract
Infrared difference spectroscopy probes vibrational changes of proteins upon their perturbation. Compared with other spectroscopic methods, it stands out by its sensitivity to the protonation state, H-bonding, and the conformation of different groups in proteins, including the peptide backbone, amino acid side chains, internal water molecules, or cofactors. In particular, the detection of protonation and H-bonding changes in a time-resolved manner, not easily obtained by other techniques, is one of the most successful applications of IR difference spectroscopy. The present review deals with the use of perturbations designed to specifically change the protein between two (or more) functionally relevant states, a strategy often referred to as reaction-induced IR difference spectroscopy. In the first half of this contribution, I review the technique of reaction-induced IR difference spectroscopy of proteins, with special emphasis given to the preparation of suitable samples and their characterization, strategies for the perturbation of proteins, and methodologies for time-resolved measurements (from nanoseconds to minutes). The second half of this contribution focuses on the spectral interpretation. It starts by reviewing how changes in H-bonding, medium polarity, and vibrational coupling affect vibrational frequencies, intensities, and bandwidths. It is followed by band assignments, a crucial aspect mostly performed with the help of isotopic labeling and site-directed mutagenesis, and complemented by integration and interpretation of the results in the context of the studied protein, an aspect increasingly supported by spectral calculations. Selected examples from the literature, predominately but not exclusively from retinal proteins, are used to illustrate the topics covered in this review.
Collapse
|
13
|
Xiong C, Wang S, Hu P, Huang L, Xue C, Yang Z, Zhou X, Wang Y, Ji H. Efficient Selective Removal of Pb(II) by Using 6-Aminothiouracil-Modified Zr-Based Organic Frameworks: From Experiments to Mechanisms. ACS APPLIED MATERIALS & INTERFACES 2020; 12:7162-7178. [PMID: 31942788 DOI: 10.1021/acsami.9b19516] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report an efficient, reusable, and selective 6-aminothiouracil (ATA)-modified Zr(IV)-based adsorbent (defined as UiO-66-ATA(Zr)) for lead ion removal in water. The adsorption equilibrium time and the maximum sorption capacity of UiO-66-ATA(Zr) for Pb(II) are, respectively, 120 min and 386.98 mg/g at pH 4 and 298 K. The Pb(II) removal rate reaches 96% at 60 min and exceeds 99% at the equilibrium state in the pH range of 2.0-5.8. Hill and pseudo-second-order models can well describe the sorption process. Pb(II) adsorbing onto UiO-66-ATA(Zr) is an irreversible, favorable chemisorption process with multimolecule participation and film diffusion control. The calculations of density functional theory, the experimental results, and the characterization analyses suggest that the binding mechanisms are the chelation and ion-exchange/electrostatic interactions between hydroxyl/amino/sulfhydryl groups of UiO-66-ATA(Zr) and Pb(II). Besides, UiO-66-ATA(Zr) has a better affinity to Pb(II) than the coexisting ions in water and an excellent repeatability at eight cycles of adsorption. Moreover, the thermodynamic study shows that UiO-66-ATA(Zr) adsorbing Pb(II) is an endothermic reaction. Thus, UiO-66-ATA(Zr) is a prospective sorbent for Pb(II) removal under the initiative of environmental protection and water purification, and this work may also provide an idea for industrial catalysis.
Collapse
Affiliation(s)
- Chao Xiong
- Fine Chemical Industry Research Institute, School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Shixing Wang
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Faculty of Metallurgical and Energy Engineering , Kunming University of Science and Technology , Kunming , Yunnan 650093 , P. R. China
| | - Peng Hu
- Fine Chemical Industry Research Institute, School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Liyun Huang
- Fine Chemical Industry Research Institute, School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Can Xue
- School of Chemical Engineering and Technology , Sun Yat-Sen University , Zhuhai 519082 , P. R. China
| | - Zujin Yang
- School of Chemical Engineering and Technology , Sun Yat-Sen University , Zhuhai 519082 , P. R. China
| | - Xiantai Zhou
- School of Chemical Engineering and Technology , Sun Yat-Sen University , Zhuhai 519082 , P. R. China
| | - Yongqing Wang
- Fine Chemical Industry Research Institute, School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
| | - Hongbing Ji
- Fine Chemical Industry Research Institute, School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , P. R. China
- School of Chemical Engineering and Technology , Sun Yat-Sen University , Zhuhai 519082 , P. R. China
| |
Collapse
|
14
|
Fu L, Wang S, Lin G, Zhang L, Liu Q, Fang J, Wei C, Liu G. Post-functionalization of UiO-66-NH 2 by 2,5-Dimercapto-1,3,4-thiadiazole for the high efficient removal of Hg(II) in water. JOURNAL OF HAZARDOUS MATERIALS 2019; 368:42-51. [PMID: 30665107 DOI: 10.1016/j.jhazmat.2019.01.025] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 01/06/2019] [Accepted: 01/10/2019] [Indexed: 05/25/2023]
Abstract
A new MOFs adsorbent was prepared by post-functionalization of UiO-66-NH2 with 2,5-Dimercapto-1,3,4-thiadiazole and utilized to remove the Hg(II) in water selectively. The UiO-66-types were detected by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM), Brunauer-Emmett-Teller (BET) and zeta potential instruments. The adsorption properties of the new MOFs adsorbent were investigated by batch experiments. The actual maximum adsorption amount was 670.5 mg/g at the optimal pH of 3. Adsorption kinetic and isotherm models were exceedingly fitted to pseudo-second-order and Langmuir/Dubinin-Radushkevich, respectively. The adsorption process and mode were geared to monolayer and chemisorption, the removal rate was directly proportional to the square of mercury ions concentration. The UiO-66-DMTD adsorbent was easy to be regenerated and the removal rate decreased by only 13.5% after ten consecutive cycles. The results of FTIR, XRD and XPS suggested that the adsorption mechanism lay on the complexation reaction between Hg(II) and thiol/nitrogen-containing groups. Moreover, compared with other competitive metal ions, viz., Zn(II), Co(IV), Ni(II), Cd(II), Mg(II), Fe(III), Ca(II) and Cu(II), the UiO-66-DMTD demonstrated an outstanding selective adsorption for Hg(II). These results manifested that the UiO-66-DMTD was a latent adsorbent for the efficient and selective removal of Hg(II) in wastewater.
Collapse
Affiliation(s)
- Likang Fu
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
| | - Shixing Wang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Guo Lin
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Libo Zhang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Qiming Liu
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China.
| | - Ju Fang
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
| | - Chenhuinan Wei
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
| | - Gang Liu
- School of Physics and Technology, Key Laboratory of Ariticial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan, 430072, China
| |
Collapse
|
15
|
Ramos S, Thielges MC. Site-Specific 1D and 2D IR Spectroscopy to Characterize the Conformations and Dynamics of Protein Molecular Recognition. J Phys Chem B 2019; 123:3551-3566. [PMID: 30848912 DOI: 10.1021/acs.jpcb.9b00969] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Proteins exist as ensembles of interconverting states on a complex energy landscape. A complete, molecular-level understanding of their function requires knowledge of the populated states and thus the experimental tools to characterize them. Infrared (IR) spectroscopy has an inherently fast time scale that can capture all states and their dynamics with, in principle, bond-specific spatial resolution, and 2D IR methods that provide richer information are becoming more routine. Although application of IR spectroscopy for investigation of proteins is challenged by spectral congestion, the issue can be overcome by site-specific introduction of amino acid side chains that have IR probe groups with frequency-resolved absorptions, which furthermore enables selective characterization of different locations in proteins. Here, we briefly introduce the biophysical methods and summarize the current progress toward the study of proteins. We then describe our efforts to apply site-specific 1D and 2D IR spectroscopy toward elucidation of protein conformations and dynamics to investigate their involvement in protein molecular recognition, in particular mediated by dynamic complexes: plastocyanin and its binding partner cytochrome f, cytochrome P450s and substrates or redox partners, and Src homology 3 domains and proline-rich peptide motifs. We highlight the advantages of frequency-resolved probes to characterize specific, local sites in proteins and uncover variation among different locations, as well as the advantage of the fast time scale of IR spectroscopy to detect rapidly interconverting states. In addition, we illustrate the greater insight provided by 2D methods and discuss potential routes for further advancement of the field of biomolecular 2D IR spectroscopy.
Collapse
Affiliation(s)
- Sashary Ramos
- Department of Chemistry , Indiana University , Bloomington , Indiana 47405 , United States
| | - Megan C Thielges
- Department of Chemistry , Indiana University , Bloomington , Indiana 47405 , United States
| |
Collapse
|
16
|
Ramos S, Horness RE, Collins JA, Haak D, Thielges MC. Site-specific 2D IR spectroscopy: a general approach for the characterization of protein dynamics with high spatial and temporal resolution. Phys Chem Chem Phys 2019; 21:780-788. [PMID: 30548035 PMCID: PMC6360950 DOI: 10.1039/c8cp06146g] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The conformational heterogeneity and dynamics of protein side chains contribute to function, but investigating exactly how is hindered by experimental challenges arising from the fast timescales involved and the spatial heterogeneity of protein structures. The potential of two-dimensional infrared (2D IR) spectroscopy for measuring conformational heterogeneity and dynamics with unprecedented spatial and temporal resolution has motivated extensive effort to develop amino acids with functional groups that have frequency-resolved absorptions to serve as probes of their protein microenvironments. We demonstrate the full advantage of the approach by selective incorporation of the probe p-cyanophenylalanine at six distinct sites in a Src homology 3 domain and the application of 2D IR spectroscopy to site-specifically characterize heterogeneity and dynamics and their contribution to cognate ligand binding. The approach revealed a wide range of microenvironments and distinct responses to ligand binding, including at the three adjacent, conserved aromatic residues that form the recognition surface of the protein. Molecular dynamics simulations performed for all the labeled proteins provide insight into the underlying heterogeneity and dynamics. Similar application of 2D IR spectroscopy and site-selective probe incorporation will allow for the characterization of heterogeneity and dynamics of other proteins, how heterogeneity and dynamics are affected by solvation and local structure, and how they might contribute to biological function.
Collapse
Affiliation(s)
- Sashary Ramos
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Rachel E. Horness
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Jessica A. Collins
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - David Haak
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Megan C. Thielges
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| |
Collapse
|
17
|
Zanobini C, Bozovic O, Jankovic B, Koziol KL, Johnson PJM, Hamm P, Gulzar A, Wolf S, Stock G. Azidohomoalanine: A Minimally Invasive, Versatile, and Sensitive Infrared Label in Proteins To Study Ligand Binding. J Phys Chem B 2018; 122:10118-10125. [DOI: 10.1021/acs.jpcb.8b08368] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Claudio Zanobini
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Olga Bozovic
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Brankica Jankovic
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Klemens L. Koziol
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland
| | | | - Peter Hamm
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Adnan Gulzar
- Biomolecular Dynamics, Institute of Physics, Albert Ludwigs University, Freiburg 79104, Germany
| | - Steffen Wolf
- Biomolecular Dynamics, Institute of Physics, Albert Ludwigs University, Freiburg 79104, Germany
| | - Gerhard Stock
- Biomolecular Dynamics, Institute of Physics, Albert Ludwigs University, Freiburg 79104, Germany
| |
Collapse
|
18
|
Stucki-Buchli B, Johnson PJM, Bozovic O, Zanobini C, Koziol KL, Hamm P, Gulzar A, Wolf S, Buchenberg S, Stock G. 2D-IR Spectroscopy of an AHA Labeled Photoswitchable PDZ2 Domain. J Phys Chem A 2017; 121:9435-9445. [DOI: 10.1021/acs.jpca.7b09675] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brigitte Stucki-Buchli
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Philip J. M. Johnson
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Olga Bozovic
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Claudio Zanobini
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Klemens L. Koziol
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Peter Hamm
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Adnan Gulzar
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Steffen Wolf
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Sebastian Buchenberg
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| | - Gerhard Stock
- Department of Chemistry, University of Zurich, 8075 Zurich, Switzerland
- Biomolecular Dynamics, Institute of
Physics, Albert Ludwigs University, 79104 Freiburg, Germany
| |
Collapse
|
19
|
Abaskharon RM, Brown SP, Zhang W, Chen J, Smith AB, Gai F. Isotope-Labeled Aspartate Sidechain as a Non-Perturbing Infrared Probe: Application to Investigate the Dynamics of a Carboxylate Buried Inside a Protein. Chem Phys Lett 2017; 683:193-198. [PMID: 29033461 DOI: 10.1016/j.cplett.2017.03.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Because of their negatively charged carboxylates, aspartate and glutamate are frequently found at the active or binding site of proteins. However, studying a specific carboxylate in proteins that contain multiple aspartates and/or glutamates via infrared spectroscopy is difficult due to spectral overlap. We show, herein, that isotopic-labeling of the aspartate sidechain can overcome this limitation as the resultant 13C=O asymmetric stretching vibration resides in a transparent region of the protein IR spectrum. Applicability of this site-specific vibrational probe is demonstrated by using it to assess the dynamics of an aspartate ion buried inside a small protein via two-dimensional infrared spectroscopy.
Collapse
Affiliation(s)
- Rachel M Abaskharon
- Department of Chemistry, University of Pennsylvania, 231 South 34 Street, Philadelphia, PA 19104, USA
| | - Stephen P Brown
- Department of Chemistry, University of Pennsylvania, 231 South 34 Street, Philadelphia, PA 19104, USA
| | - Wenkai Zhang
- Ultrafast Optical Processes Laboratory, University of Pennsylvania, 231 South 34 Street, Philadelphia, PA 19104, USA
| | - Jianxin Chen
- Ultrafast Optical Processes Laboratory, University of Pennsylvania, 231 South 34 Street, Philadelphia, PA 19104, USA
| | - Amos B Smith
- Department of Chemistry, University of Pennsylvania, 231 South 34 Street, Philadelphia, PA 19104, USA
| | - Feng Gai
- Department of Chemistry, University of Pennsylvania, 231 South 34 Street, Philadelphia, PA 19104, USA.,Ultrafast Optical Processes Laboratory, University of Pennsylvania, 231 South 34 Street, Philadelphia, PA 19104, USA
| |
Collapse
|
20
|
Lórenz-Fonfría VA, Muders V, Schlesinger R, Heberle J. Changes in the hydrogen-bonding strength of internal water molecules and cysteine residues in the conductive state of channelrhodopsin-1. J Chem Phys 2015; 141:22D507. [PMID: 25494778 DOI: 10.1063/1.4895796] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Water plays an essential role in the structure and function of proteins, particularly in the less understood class of membrane proteins. As the first of its kind, channelrhodopsin is a light-gated cation channel and paved the way for the new and vibrant field of optogenetics, where nerve cells are activated by light. Still, the molecular mechanism of channelrhodopsin is not understood. Here, we applied time-resolved FT-IR difference spectroscopy to channelrhodopsin-1 from Chlamydomonas augustae. It is shown that the (conductive) P2(380) intermediate decays with τ ≈ 40 ms and 200 ms after pulsed excitation. The vibrational changes between the closed and the conductive states were analyzed in the X-H stretching region (X = O, S, N), comprising vibrational changes of water molecules, sulfhydryl groups of cysteine side chains and changes of the amide A of the protein backbone. The O-H stretching vibrations of "dangling" water molecules were detected in two different states of the protein using H2 (18)O exchange. Uncoupling experiments with a 1:1 mixture of H2O:D2O provided the natural uncoupled frequencies of the four O-H (and O-D) stretches of these water molecules, each with a very weakly hydrogen-bonded O-H group (3639 and 3628 cm(-1)) and with the other O-H group medium (3440 cm(-1)) to moderately strongly (3300 cm(-1)) hydrogen-bonded. Changes in amide A and thiol vibrations report on global and local changes, respectively, associated with the formation of the conductive state. Future studies will aim at assigning the respective cysteine group(s) and at localizing the "dangling" water molecules within the protein, providing a better understanding of their functional relevance in CaChR1.
Collapse
Affiliation(s)
| | - Vera Muders
- Genetic Biophysics, Freie Universität Berlin, 14195 Berlin, Germany
| | | | - Joachim Heberle
- Experimental Molecular Biophysics, Freie Universität Berlin, 14195 Berlin, Germany
| |
Collapse
|
21
|
Guo Q, Pagano P, Li YL, Kohen A, Cheatum CM. Line shape analysis of two-dimensional infrared spectra. J Chem Phys 2015; 142:212427. [PMID: 26049447 PMCID: PMC4409623 DOI: 10.1063/1.4918350] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/06/2015] [Indexed: 12/19/2022] Open
Abstract
Ultrafast two-dimensional infrared (2D IR) spectroscopy probes femtosecond to picosecond time scale dynamics ranging from solvation to protein motions. The frequency-frequency correlation function (FFCF) is the quantitative measure of the spectral diffusion that reports those dynamics and, within certain approximations, can be extracted directly from 2D IR line shapes. A variety of methods have been developed to extract the FFCF from 2D IR spectra, which, in principle, should give the same FFCF parameters, but the complexity of real experimental systems will affect the results of these analyses differently. Here, we compare five common analysis methods using both simulated and experimental 2D IR spectra to understand the effects of apodization, anharmonicity, phasing errors, and finite signal-to-noise ratios on the results of each of these analyses. Our results show that although all of the methods can, in principle, yield the FFCF under idealized circumstances, under more realistic experimental conditions they behave quite differently, and we find that the centerline slope analysis yields the best compromise between the effects we test and is most robust to the distortions that they cause.
Collapse
Affiliation(s)
- Qi Guo
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Philip Pagano
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Yun-Liang Li
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Amnon Kohen
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Christopher M Cheatum
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, USA and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, USA
| |
Collapse
|
22
|
Shaw DJ, Adamczyk K, Frederix PWJM, Simpson N, Robb K, Greetham GM, Towrie M, Parker AW, Hoskisson PA, Hunt NT. Multidimensional infrared spectroscopy reveals the vibrational and solvation dynamics of isoniazid. J Chem Phys 2015; 142:212401. [DOI: 10.1063/1.4914097] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Daniel J. Shaw
- Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
- Strathclyde Institute for Pharmacy and Biomedical Sciences (SIPBS), University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, United Kingdom
| | - Katrin Adamczyk
- Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| | - Pim W. J. M. Frederix
- Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| | - Niall Simpson
- Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| | - Kirsty Robb
- Strathclyde Institute for Pharmacy and Biomedical Sciences (SIPBS), University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, United Kingdom
| | - Gregory M. Greetham
- STFC Rutherford Appleton Laboratory, Central Laser Facility, Research Complex at Harwell, Didcot OX11 0QX, United Kingdom
| | - Michael Towrie
- STFC Rutherford Appleton Laboratory, Central Laser Facility, Research Complex at Harwell, Didcot OX11 0QX, United Kingdom
| | - Anthony W. Parker
- STFC Rutherford Appleton Laboratory, Central Laser Facility, Research Complex at Harwell, Didcot OX11 0QX, United Kingdom
| | - Paul A. Hoskisson
- Strathclyde Institute for Pharmacy and Biomedical Sciences (SIPBS), University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, United Kingdom
| | - Neil T. Hunt
- Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| |
Collapse
|
23
|
Koziol KL, Johnson PJM, Stucki-Buchli B, Waldauer SA, Hamm P. Fast infrared spectroscopy of protein dynamics: advancing sensitivity and selectivity. Curr Opin Struct Biol 2015; 34:1-6. [PMID: 25900180 DOI: 10.1016/j.sbi.2015.03.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 03/27/2015] [Accepted: 03/31/2015] [Indexed: 01/08/2023]
Abstract
2D-IR spectroscopy has matured to a powerful technique to study the structure and dynamics of peptides, but its extension to larger proteins is still in its infancy, the major limitations being sensitivity and selectivity. Site-selective information requires measuring single vibrational probes at sub-millimolar concentrations where most proteins are still stable, which is a severe challenge for conventional (FT)IR spectroscopy. Besides its ultrafast time-resolution, a so far largely underappreciated potential of 2D-IR spectroscopy lies in its sensitivity gain. The present paper sets the goals and outlines strategies how to use that sensitivity gain together with properly designed vibrational labels to make IR spectroscopy a versatile tool to study a wide class of proteins.
Collapse
Affiliation(s)
- Klemens L Koziol
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland
| | - Philip J M Johnson
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland
| | - Brigitte Stucki-Buchli
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland
| | - Steven A Waldauer
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland
| | - Peter Hamm
- Department of Chemistry, University of Zurich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland.
| |
Collapse
|
24
|
Description of cross-peaks induced by intermolecular vibrational energy transfer in two-dimensional infrared spectroscopy. Chem Phys 2015. [DOI: 10.1016/j.chemphys.2015.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
25
|
Abstract
Infrared spectroscopy has played an instrumental role in the study of a wide variety of biological questions. However, in many cases, it is impossible or difficult to rely on the intrinsic vibrational modes of biological molecules of interest, such as proteins, to reveal structural and environmental information in a site-specific manner. To overcome this limitation, investigators have dedicated many recent efforts to the development and application of various extrinsic vibrational probes that can be incorporated into biological molecules and used to site-specifically interrogate their structural or environmental properties. In this review, we highlight recent advancements in this rapidly growing research area.
Collapse
|
26
|
Minkov VS, Boldyreva EV. Contribution of Weak S–H···O Hydrogen Bonds to the Side Chain Motions in d,l-Homocysteine on Cooling. J Phys Chem B 2014; 118:8513-23. [DOI: 10.1021/jp503154x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vasily S. Minkov
- Novosibirsk State University, 2 Pirogov
str., 630090 Novosibirsk, Russian Federation
- Institute
of Solid State Chemistry and Mechanochemistry Siberian Branch of Russian Academy of Sciences, 18 Kutateladze str., 630128 Novosibirsk, Russian Federation
| | - Elena V. Boldyreva
- Novosibirsk State University, 2 Pirogov
str., 630090 Novosibirsk, Russian Federation
- Institute
of Solid State Chemistry and Mechanochemistry Siberian Branch of Russian Academy of Sciences, 18 Kutateladze str., 630128 Novosibirsk, Russian Federation
| |
Collapse
|
27
|
van Wilderen LJGW, Kern-Michler D, Müller-Werkmeister HM, Bredenbeck J. Vibrational dynamics and solvatochromism of the label SCN in various solvents and hemoglobin by time dependent IR and 2D-IR spectroscopy. Phys Chem Chem Phys 2014; 16:19643-53. [DOI: 10.1039/c4cp01498g] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The vibrational label SCN is used to report on local structural dynamics in a protein revealing spectral diffusion on a picosecond scale. The SCN spectra are compared to the response of methylthiocyanate in solvents with different polarity and hydrogen-bonding capabilities.
Collapse
Affiliation(s)
| | - Daniela Kern-Michler
- Johann Wolfgang Goethe-University
- Institute of Biophysics
- Frankfurt am Main, Germany
| | | | - Jens Bredenbeck
- Johann Wolfgang Goethe-University
- Institute of Biophysics
- Frankfurt am Main, Germany
| |
Collapse
|
28
|
Choi JH, Kwak KW, Cho M. Computational infrared and two-dimensional infrared photon echo spectroscopy of both wild-type and double mutant myoglobin-CO proteins. J Phys Chem B 2013; 117:15462-78. [PMID: 23869523 DOI: 10.1021/jp405210s] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The CO stretching mode of both wild-type and double mutant ( T67R / S92D ) MbCO (carbonmonoxymyoglobin) proteins is an ideal infrared (IR) probe for studying the local electrostatic environment inside the myoglobin heme pocket. Recently, to elucidate the conformational switching dynamics between two distinguishable states, extensive IR absorption, IR pump-probe, and two-dimensional (2D) IR spectroscopic studies for various mutant MbCO's have been performed by the Fayer group. They showed that the 2D IR spectroscopy of the double mutant, which has a peroxidase enzyme activity, reveals a rapid chemical exchange between two distinct states, whereas that of the wild-type does not. Despite the fact that a few simulation studies on these systems were already performed and reported, such complicated experimental results have not been fully reproduced nor described in terms of conformational state-to-state transition processes. Here, we first develop a distributed vibrational solvatochromic charge model for describing the CO stretch frequency shift reflecting local electric potential changes. Then, by carrying out molecular dynamic simulations of the two MbCO's and examining their CO frequency trajectories, it becomes possible to identify a proper reaction coordinate consisting of His64 imidazole ring rotation and its distance to the CO ligand. From the 2D surfaces of the resulting potential of mean forces, the spectroscopically distinguished A1 and A3 states of the wild-type as well as two more substates of the double mutant are identified and their vibrational frequencies and distributions are separately examined. Our simulated IR absorption and 2D IR spectra of the two MbCO's are directly compared with the previous experimental results reported by the Fayer group. The chemical exchange rate constants extracted from the two-state kinetic analyses of the simulated 2D IR spectra are in excellent agreement with the experimental values. On the basis of the quantitative agreement between the simulated spectra and experimental ones, we further examine the conformational differences in the heme pockets of the two proteins and show that the double mutation, T67R / S92D , suppresses the A1 population, restricts the imidazole ring rotation, and increases hydrogen-bond strength between the imidazole Nε-H and the oxygen atom of the CO ligand. It is believed that such delicate change of distal His64 imidazole ring dynamics induced by the double mutation may be responsible for its enhanced peroxidase catalytic activity as compared to the wild-type myoglobin.
Collapse
Affiliation(s)
- Jun-Ho Choi
- Department of Chemistry, Korea University , Seoul 136-713, Korea
| | | | | |
Collapse
|
29
|
Rock W, Li YL, Pagano P, Cheatum CM. 2D IR spectroscopy using four-wave mixing, pulse shaping, and IR upconversion: a quantitative comparison. J Phys Chem A 2013; 117:6073-83. [PMID: 23687988 DOI: 10.1021/jp312817t] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent technological advances have led to major changes in the apparatuses used to collect 2D IR spectra. Pulse shaping offers several advantages including rapid data collection, inherent phase stability, and phase-cycling capabilities. Visible array detection via upconversion allows the use of visible detectors that are cheaper, faster, more sensitive, and less noisy than IR detectors. However, despite these advantages, many researchers are reluctant to implement these technologies. Here we present a quantitative study of the S/N of 2D IR spectra collected with a traditional four-wave mixing (FWM) apparatus, with a pulse shaping apparatus, and with visible detection via upconversion to address the question of whether weak chromophores at low concentrations are still accessible with such an apparatus. We find that the enhanced averaging capability of the pulse shaping apparatus enables the detection of small signals that would be challenging to measure even with the traditional FWM apparatus, and we demonstrate this ability on a sample of cyanylated dihydrofolate reductase.
Collapse
Affiliation(s)
- William Rock
- Department of Chemistry and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, USA
| | | | | | | |
Collapse
|
30
|
Kim H, Cho M. Infrared Probes for Studying the Structure and Dynamics of Biomolecules. Chem Rev 2013; 113:5817-47. [DOI: 10.1021/cr3005185] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Heejae Kim
- Department of Chemistry, Korea University, Seoul 136-713, Korea
| | - Minhaeng Cho
- Department of Chemistry, Korea University, Seoul 136-713, Korea
- Multidimensional Spectroscopy Laboratory, Korea Basic Science Institute,
Seoul 136-713, Korea
| |
Collapse
|
31
|
Saggu M, Levinson NM, Boxer SG. Experimental quantification of electrostatics in X-H···π hydrogen bonds. J Am Chem Soc 2012; 134:18986-97. [PMID: 23098379 PMCID: PMC3511793 DOI: 10.1021/ja305575t] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hydrogen bonds are ubiquitous in chemistry and biology. The physical forces that govern hydrogen-bonding interactions have been heavily debated, with much of the discussion focused on the relative contributions of electrostatic vs quantum mechanical effects. In principle, the vibrational Stark effect, the response of a vibrational mode to electric field, can provide an experimental method for parsing such interactions into their electrostatic and nonelectrostatic components. In a previous study we showed that, in the case of relatively weak O-H···π hydrogen bonds, the O-H bond displays a linear response to an electric field, and we exploited this response to demonstrate that the interactions are dominated by electrostatics (Saggu, M.; Levinson, N. M.; Boxer, S. G. J. Am. Chem. Soc.2011, 133, 17414-17419). Here we extend this work to other X-H···π interactions. We find that the response of the X-H vibrational probe to electric field appears to become increasingly nonlinear in the order O-H < N-H < S-H. The observed effects are consistent with differences in atomic polarizabilities of the X-H groups. Nonetheless, we find that the X-H stretching vibrations of the model compounds indole and thiophenol report quantitatively on the electric fields they experience when complexed with aromatic hydrogen-bond acceptors. These measurements can be used to estimate the electrostatic binding energies of the interactions, which are found to agree closely with the results of energy calculations. Taken together, these results highlight that with careful calibration vibrational probes can provide direct measurements of the electrostatic components of hydrogen bonds.
Collapse
Affiliation(s)
- Miguel Saggu
- Department of Chemistry, Stanford University, Stanford, CA 94305-5012, USA
| | | | - Steven G. Boxer
- Department of Chemistry, Stanford University, Stanford, CA 94305-5012, USA
| |
Collapse
|
32
|
Bloem R, Koziol K, Waldauer SA, Buchli B, Walser R, Samatanga B, Jelesarov I, Hamm P. Ligand Binding Studied by 2D IR Spectroscopy Using the Azidohomoalanine Label. J Phys Chem B 2012; 116:13705-12. [DOI: 10.1021/jp3095209] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Robbert Bloem
- Institute of Physical Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Klemens Koziol
- Institute of Physical Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Steven A. Waldauer
- Institute of Physical Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Brigitte Buchli
- Institute of Physical Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Reto Walser
- Institute of Physical Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Brighton Samatanga
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
- Institute of Molecular Biology
and Biophysics, ETH Zurich, Zurich 8093,
Switzerland
| | - Ilian Jelesarov
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
| | - Peter Hamm
- Institute of Physical Chemistry, University of Zurich, Zurich 8057, Switzerland
| |
Collapse
|
33
|
Xue L, Zou F, Zhao Y, Huang X, Qu Y. Nitrile group as infrared probe for the characterization of the conformation of bovine serum albumin solubilized in reverse micelles. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 97:858-863. [PMID: 22902928 DOI: 10.1016/j.saa.2012.07.076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 07/08/2012] [Accepted: 07/22/2012] [Indexed: 06/01/2023]
Abstract
Infrared spectroscopy is a powerful technique for structure characterization. For a protein hosted in a reversed micellar medium, the spectral features of the protein are always interfered by the IR absorption bands of the medium in addition to the congestion in their IR spectra. Fortunately, there is a transparent window in the 2500-2200 cm(-1) region. Incorporation of a vibrational probe with IR absorption frequencies in this region into proteins represents a promising strategy for the study of the conformation of a protein in a reverse micelle. In the present work, we incorporated 4-cyanobenzyl group (CN) into bovine serum albumin (BSA) via cysteine alkylation reactions under mild conditions. Circular dichroism spectroscopy showed that the CN modified BSA (CNBSA) could retain its conformation. When CNBSA was hosted in AOT reverse micelle, it was found that the nitrile group on BSA was sensitive to the conformational change of BSA induced by urea as an additive in the reverse micelle. The peak splitting of nitrile group was also observed when the size of AOT reverse micelle and the concentration of an electrolyte were varied. Obviously, the shift of the IR absorption peak and/or peak splitting of nitrile group on BSA are correlated with the change of BSA conformation in AOT reverse micelle. So we conclude that the nitrile infrared probe can be used to study protein conformation in a reverse micelle.
Collapse
Affiliation(s)
- Luyan Xue
- Key Laboratory of Colloid & Interface Chemistry of the Education Ministry of China, Shandong University, Jinan 250100, PR China
| | | | | | | | | |
Collapse
|
34
|
Chen H, Bian H, Li J, Wen X, Zheng J. Ultrafast multiple-mode multiple-dimensional vibrational spectroscopy. INT REV PHYS CHEM 2012. [DOI: 10.1080/0144235x.2012.733116] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
35
|
Choi JH, Raleigh D, Cho M. Azido Homoalanine is a Useful Infrared Probe for Monitoring Local Electrostatistics and Sidechain Solvation in Proteins. J Phys Chem Lett 2011; 2:2158-2162. [PMID: 22389750 PMCID: PMC3290331 DOI: 10.1021/jz200980g] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The use of IR probes to monitor protein structure, deduce local electric field, and investigate the mechanism of enzyme catalysis and protein folding has attracted increasing attention. Here, the azidohomoalanine (Aha) is considered as a useful IR probe. The intricate details of the distinct effects of backbone peptide bonds and H-bonded water molecules on the azido stretch mode of the IR probe Aha were revealed by carrying out QM/MM MD simulations of two variants of the protein NTL9, NTL9-Met1Aha and NTL9-Ile4Aha and comparing the resulting simulated IR spectra with experiments.
Collapse
Affiliation(s)
- Jun-Ho Choi
- Department of Chemistry, Korea University, Seoul 136-701, Korea
| | - Daniel Raleigh
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, NY 11794, U.S.A
| | - Minhaeng Cho
- Department of Chemistry, Korea University, Seoul 136-701, Korea
- Multidimensional Spectroscopy Laboratory, Korea Basic Science Institute, Seoul 136-713, Korea
- Corresponding Author:
| |
Collapse
|
36
|
Nicodemus RA, Corcelli SA, Skinner JL, Tokmakoff A. Collective Hydrogen Bond Reorganization in Water Studied with Temperature-Dependent Ultrafast Infrared Spectroscopy. J Phys Chem B 2011; 115:5604-16. [DOI: 10.1021/jp111434u] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Rebecca A. Nicodemus
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - S. A. Corcelli
- Department of Chemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - J. L. Skinner
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Andrei Tokmakoff
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
37
|
Sage JT, Zhang Y, McGeehan J, Ravelli RBG, Weik M, van Thor JJ. Infrared protein crystallography. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:760-77. [PMID: 21376143 DOI: 10.1016/j.bbapap.2011.02.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 02/22/2011] [Accepted: 02/23/2011] [Indexed: 11/19/2022]
Abstract
We consider the application of infrared spectroscopy to protein crystals, with particular emphasis on exploiting molecular orientation through polarization measurements on oriented single crystals. Infrared microscopes enable transmission measurements on individual crystals using either thermal or nonthermal sources, and can accommodate flow cells, used to measure spectral changes induced by exposure to soluble ligands, and cryostreams, used for measurements of flash-cooled crystals. Comparison of unpolarized infrared measurements on crystals and solutions probes the effects of crystallization and can enhance the value of the structural models refined from X-ray diffraction data by establishing solution conditions under which they are most relevant. Results on several proteins are consistent with similar equilibrium conformational distributions in crystal and solutions. However, the rates of conformational change are often perturbed. Infrared measurements also detect products generated by X-ray exposure, including CO(2). Crystals with favorable symmetry exhibit infrared dichroism that enhances the synergy with X-ray crystallography. Polarized infrared measurements on crystals can distinguish spectral contributions from chemically similar sites, identify hydrogen bonding partners, and, in opportune situations, determine three-dimensional orientations of molecular groups. This article is part of a Special Issue entitled: Protein Structure and Function in the Crystalline State.
Collapse
Affiliation(s)
- J Timothy Sage
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA 02115, USA.
| | | | | | | | | | | |
Collapse
|
38
|
Keating CS, McClure BA, Rack JJ, Rubtsov IV. Sulfoxide stretching mode as a structural reporter via dual-frequency two-dimensional infrared spectroscopy. J Chem Phys 2011; 133:144513. [PMID: 20950023 DOI: 10.1063/1.3482708] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The S=O stretching mode in sulfoxides, having a frequency in the 950-1150 cm(-1) range, is tested as a structural label via dual-frequency two-dimensional infrared (2DIR) spectroscopy. The properties of this structural reporter are studied in several compounds, including (4,4(')-dimethyl-2,2(')-bipyridyl)(o-methylsulfinylbenzoate) ruthenium II, [Ru(dmb)(2)(BzSO)](+), (RuBzSO), octylsulfinylpropionic acid (OSPA), and o- and p-methylsulfinyl-benzoic acid (oMSBA and pMSBA). The mode assignment in the fingerprint region for these compounds is made using a combination of density functional theory calculations and 2DIR and relaxation-assisted 2DIR (RA 2DIR) spectroscopies. The SO stretching mode frequency and IR intensity demonstrate substantial sensitivity to the molecular structure. Multiple cross peaks of the C=O and S=O stretching modes with modes in the fingerprint region (930-1450 cm(-1)) were recorded. The 2DIR and RA 2DIR spectra focusing at interactions of a high-frequency mode of a ligand with the modes in the fingerprint region provide a spectral fingerprint of a compound and help mode assignment in the often congested fingerprint region. The cross-peak amplitudes in oMSBA, pMSBA, and OSPA were compared with the theoretical predictions based on the computed values for the off-diagonal anharmonicities and a reasonable match is found. The SO stretching mode provides means for assigning other modes in the fingerprint region and constitutes a promising structural reporter for the 2DIR and RA 2DIR spectroscopy measurements.
Collapse
|
39
|
Woys AM, Lin YS, Reddy AS, Xiong W, de Pablo JJ, Skinner JL, Zanni MT. 2D IR Line Shapes Probe Ovispirin Peptide Conformation and Depth in Lipid Bilayers. J Am Chem Soc 2010; 132:2832-8. [DOI: 10.1021/ja9101776] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Ann Marie Woys
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, and Department of Chemical Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691
| | - Yu-Shan Lin
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, and Department of Chemical Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691
| | - Allam S. Reddy
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, and Department of Chemical Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691
| | - Wei Xiong
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, and Department of Chemical Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691
| | - Juan J. de Pablo
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, and Department of Chemical Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691
| | - James L. Skinner
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, and Department of Chemical Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691
| | - Martin T. Zanni
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, and Department of Chemical Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691
| |
Collapse
|
40
|
Helbing J, Bonmarin M. Vibrational circular dichroism signal enhancement using self-heterodyning with elliptically polarized laser pulses. J Chem Phys 2009; 131:174507. [DOI: 10.1063/1.3256224] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
41
|
Bian H, Zhao W, Zheng J. Intermolecular vibrational energy exchange directly probed with ultrafast two dimensional infrared spectroscopy. J Chem Phys 2009; 131:124501. [DOI: 10.1063/1.3212618] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
42
|
Rubtsov IV. Relaxation-assisted two-dimensional infrared (RA 2DIR) method: accessing distances over 10 A and measuring bond connectivity patterns. Acc Chem Res 2009; 42:1385-94. [PMID: 19462972 DOI: 10.1021/ar900008p] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Development of new approaches for measuring three-dimensional structures and dynamics of structural changes is important for a number of natural sciences, including structural biology, where it can lead to understanding the physical bases of molecular recognition and catalysis. A two-dimensional infrared (2DIR) spectroscopy method permits measuring pairwise interactions among vibrational modes in molecules providing a molecular scale ruler for delivering structural constraints, such as the distances between the vibrational modes, angles between their transition dipoles, and the energy-transfer rates between them. While there is a large variety of systems that have recently been interrogated using 2DIR, questions remain of how to measure structural features of larger molecules. The challenges of working with larger molecules, such as proteins, include very congested vibrational spectra, a small range of distances accessible by the 2DIR method, and sensitivity issues. This Account describes the efforts of our laboratory to overcome some of these challenges. First, we discuss the dual-frequency 2DIR approach, which provides the highest selectivity to a particular pair of vibrational reporters and highest sensitivity. Second, we describe our steps in developing vibrational labels, novel for 2DIR, such as C identical withN and C-D stretching modes that have frequencies in the water transparency region, as well as the modes in the fingerprint region. The schemes suitable for labeling amino acids are discussed. Next, we describe the novel relaxation-assisted 2DIR (RA 2DIR) method, developed in our laboratory. The method uses vibrational relaxation and vibrational energy transport in molecules and the thermalization process on a molecular scale, to generate stronger cross-peaks. An 18-fold cross-peak amplification was observed for the modes separated by about 11 A using the RA 2DIR method, and larger amplifications are expected for larger distances between the modes. Large amplification provided by the RA 2DIR method enhances the sensitivity of 2DIR spectroscopy and permits longer range structural measurements. In addition to generating stronger cross-peaks, a correlation of the energy transport time with the intermode distance is demonstrated. This correlation permits measurements of mode-connectivity patterns in molecules much similar to those available in total correlation spectroscopy (TOCSY) and heteronuclear multiple-bond correlation (HMBC) methods of 2D nuclear magnetic resonance (NMR) spectroscopy. It is our hope that, with a proper calibration, the RA 2DIR method will permit speedy assessments of distances and the bond connectivity patterns in molecules and reach the level of an analytical method.
Collapse
Affiliation(s)
- Igor V. Rubtsov
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| |
Collapse
|
43
|
Miller CS, Ploetz EA, Cremeens ME, Corcelli SA. Carbon-deuterium vibrational probes of peptide conformation: alanine dipeptide and glycine dipeptide. J Chem Phys 2009; 130:125103. [PMID: 19334896 DOI: 10.1063/1.3100185] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The utility of alpha-carbon deuterium-labeled bonds (C(alpha)-D) as infrared reporters of local peptide conformation was investigated for two model dipeptide compounds: C(alpha)-D labeled alanine dipeptide (Adp-d(1)) and C(alpha)-D(2) labeled glycine dipeptide (Gdp-d(2)). These model compounds adopt structures that are analogous to the motifs found in larger peptides and proteins. For both Adp-d(1) and Gdp-d(2), we systematically mapped the entire conformational landscape in the gas phase by optimizing the geometry of the molecule with the values of phi and psi, the two dihedral angles that are typically used to characterize the backbone structure of peptides and proteins, held fixed on a uniform grid with 7.5 degrees spacing. Since the conformations were not generally stationary states in the gas phase, we then calculated anharmonic C(alpha)-D and C(alpha)-D(2) stretch transition frequencies for each structure. For Adp-d(1) the C(alpha)-D stretch frequency exhibited a maximum variability of 39.4 cm(-1) between the six stable structures identified in the gas phase. The C(alpha)-D(2) frequencies of Gdp-d(2) show an even more substantial difference between its three stable conformations: there is a 40.7 cm(-1) maximum difference in the symmetric C(alpha)-D(2) stretch frequencies and an 81.3 cm(-1) maximum difference in the asymmetric C(alpha)-D(2) stretch frequencies. Moreover, the splitting between the symmetric and asymmetric C(alpha)-D(2) stretch frequencies of Gdp-d(2) is remarkably sensitive to its conformation.
Collapse
Affiliation(s)
- C S Miller
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | | | | | | |
Collapse
|
44
|
Andresen ER, Hamm P. Site-specific difference 2D-IR spectroscopy of bacteriorhodopsin. J Phys Chem B 2009; 113:6520-7. [PMID: 19358550 DOI: 10.1021/jp810397u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We demonstrate the extension of the principle of difference Fourier transform infrared (FTIR) spectroscopy to difference 2D-IR spectroscopy. To this end, we measure difference 2D-IR spectra of the protein bacteriorhodopsin in its early J- and K-intermediates. By comparing with the static 2D-IR spectrum of the protonated Schiff base of all-trans retinal, we demonstrate that the 2D-IR spectrum of the all-trans retinal chromophore in bacteriorhodopsin can be measured with the background from the remainder of the protein completely suppressed. We discuss several models to interpret the detailed line shape of the difference 2D-IR spectrum.
Collapse
Affiliation(s)
- Esben Ravn Andresen
- Physikalisch-Chemisches Institut, Universitat Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | | |
Collapse
|
45
|
Naraharisetty SRG, Kasyanenko VM, Zimmermann J, Thielges MC, Romesberg FE, Rubtsov IV. C-D modes of deuterated side chain of leucine as structural reporters via dual-frequency two-dimensional infrared spectroscopy. J Phys Chem B 2009; 113:4940-6. [PMID: 19298041 DOI: 10.1021/jp8112446] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Perdeuteration of the side chains of amino acids such as leucine results in appearance of reasonably strong absorption peaks around 2050-2220 cm(-1) that belong to the CD stretching modes and exhibit extinction coefficients of up to 120 M(-1) cm(-1). The properties of the CD stretching transitions in leucine-d(10) as structural labels are studied via the methods of two-dimensional infrared (2DIR) spectroscopy. The cross peaks caused by interactions of the CD stretching modes with amide I (Am-I), CO, and amide II (Am-II) modes are obtained by the dual-frequency 2DIR method. The CD stretching peaks in leucine-d(10) are characterized using DFT computational modeling as well as relaxation-assisted 2DIR (RA 2DIR) measurements. The RA 2DIR measurements showed different enhancements and different energy transport times (arrival times) for different CD/Am-II and CD/CO cross peaks; a correlation between the intermode distance, the arrival time, and the amplification factor is reported. We demonstrated that the CD transitions of leucine-d(10) amino acid can serve as convenient structural reporters via the dual-frequency 2DIR methods and discussed the potential of leucine-d(10) and other amino acids with deuterium-labeled side chains as probes of protein structure and dynamics.
Collapse
|
46
|
Lin YS, Shorb JM, Mukherjee P, Zanni MT, Skinner JL. Empirical amide I vibrational frequency map: application to 2D-IR line shapes for isotope-edited membrane peptide bundles. J Phys Chem B 2009; 113:592-602. [PMID: 19053670 PMCID: PMC2633092 DOI: 10.1021/jp807528q] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The amide I vibrational mode, primarily associated with peptide-bond carbonyl stretches, has long been used to probe the structures and dynamics of peptides and proteins by infrared (IR) spectroscopy. A number of ab initio-based amide I vibrational frequency maps have been developed for calculating IR line shapes. In this paper, a new empirical amide I vibrational frequency map is developed. To evaluate its performance, we applied this map to a system of isotope-edited CD3-zeta membrane peptide bundles in aqueous solution. The calculated 2D-IR diagonal line widths vary from residue to residue and show an asymmetric pattern as a function of position in the membrane. The theoretical results are in fair agreement with experiments on the same system. Through analysis of the computed frequency time-correlation functions, it is found that the 2D-IR diagonal widths are dominated by contributions from the inhomogeneous frequency distributions, from which it follows that these widths are a good probe of the extent of local structural fluctuations. Thus, the asymmetric pattern of line widths follows from the asymmetric structure of the bundle in the membrane.
Collapse
Affiliation(s)
- Y-S Lin
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
| | | | | | | | | |
Collapse
|
47
|
Lindquist BA, Furse KE, Corcelli SA. Nitrile groups as vibrational probes of biomolecular structure and dynamics: an overview. Phys Chem Chem Phys 2009; 11:8119-32. [DOI: 10.1039/b908588b] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
48
|
Hunt NT. 2D-IR spectroscopy: ultrafast insights into biomolecule structure and function. Chem Soc Rev 2009; 38:1837-48. [DOI: 10.1039/b819181f] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
49
|
Backus EHG, Garrett-Roe S, Hamm P. Phasing problem of heterodyne-detected two-dimensional infrared spectroscopy. OPTICS LETTERS 2008; 33:2665-2667. [PMID: 19015702 DOI: 10.1364/ol.33.002665] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A rigorous method is presented to measure and adjust the phase difference between the two pulse pairs used in heterodyne-detected 2D-IR spectroscopy with an accuracy better than |Deltaphi|=0.1 rad. The method, which can easily be automated, avoids the otherwise tedious measurement of the much weaker pump-probe spectrum as a reference, which is the commonly used approach to phase 2D-IR spectra in a postprocessing step.
Collapse
Affiliation(s)
- Ellen H G Backus
- Physikalisch-Chemisches Institut, Universität Zürich, Zürich, Switzerland
| | | | | |
Collapse
|
50
|
Lindquist BA, Haws RT, Corcelli SA. Optimized Quantum Mechanics/Molecular Mechanics Strategies for Nitrile Vibrational Probes: Acetonitrile and para-Tolunitrile in Water and Tetrahydrofuran. J Phys Chem B 2008; 112:13991-4001. [DOI: 10.1021/jp804900u] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Beth A. Lindquist
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Ryan T. Haws
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Steven A. Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| |
Collapse
|